Effect of Plastics on Human Health

Plastic has become a considerable part of our daily modern lives. When introduced in the 1950’s, plastic was greatly praised for its convenience, pliability (in comparison to glass) and cheap high production rates. The belief was that our world could only benefit from the use of this versatile material, but that has not proven to be true.

Where Do They Come From?

The effects of plastic on our environment and ocean is well known and has resulted in a tremendous global movement against the use of the versatile material. The effects of plastic on the human body, however, is less well-known and awareness needs to be raised around this topic. Human health risks from plastics can stem from their monomeric building blocks (e.g., Bisphenol A), their additives (e.g., plasticizers) or from a combination of the two (e.g., antimicrobial polycarbonate). [1]

BPA’s - Bisphenol A

The most notorious toxin in plastic is BPA. BPA is a human-made chemical that gives rigidity to plastics and is also used in food can linings. This prevents degradation of the metal. BPA is used in receipts to stabilize the ink. You may notice some water bottles, baby bottles and lunch box containers proudly advertising that their product is BPA free. [2] [3] Note that some BPA free products contain Bisphenol-S, which is often a more toxic phenol. BPA is a hormone disruptor and is linked to a host of health issues. [2] [3] BPA can be found in water bottles, canned foods and cash register receipts. [3]

Phthalates
Phthalates help to make plastic softer and more pliable. Phthalates gained popularity when the plastic blood bag replaced the glass bottle that stored blood. [4] Due to the fact that the phthalate chemical is not tightly bound to the other molecules in the plastic, they easily migrate from the plastic. [4] Phthalates are endocrine disruptors and can be found in food containers, plastic toys, plastic bags and wraps. Phthalates can be present in flooring and in personal care products, such as shampoos, lotions, make-up, perfumes, etc. Note that processed foods and high fat dairy are particularly high in phthalates. [4]

Polyvinyl Chloride - PVC
PVC releases dioxins, phthalates, vinyl chloride, ethylene dichloride, lead, cadmium and other toxic chemicals into the environment in its production. [5] It can leech many of these harmful chemicals into the water or food that it’s being used to contain. PVC is used in plumbing pipes and electrical cable insulation as well as in the production of bottles and ATM cards. [5]

How do these plastics get into my body?

Toxins from plastic enter the human body through various routes. Exposure to phthalates are primarily through ingestion, inhalation and dermal contact. [5] Frequent use of creams, hair sprays and colognes may increase your exposure. [5] An important route of phthalate exposure to note is through certain medical procedures or devices. [4] Blood bags are a common offender in this category as phthalates in the bag interact with red blood cells and leech into the blood. [4] Patients who require frequent blood transfusions, dialysis or extracorporeal membrane oxygenation are being exposed to phthalates with every treatment received. [4] Particularly vulnerable groups are infants and pregnant women. [4] [5]

BPA enters the human body mostly through foods stored in cans, water bottles, food storage containers and baby bottles. [2] [3] A study published in the American Journal of Epidemiology confirms that concentrations of BPA are highest in the amniotic fluid of pregnant women of 15 - 18 week gestation. [2] Daily intake of BPA’s were higher in males than females, whilst older individuals (60+ years) had the lowest estimated intakes. [3] More research is needed to understand how prenatal exposure to BPA’s will affect our future generations. [2] [3]


Microplastics are defined as plastic particles measuring less than 5mm. Evidence has shown that microplastics have been found in human stool samples and scientists speculate that one route of exposure could be through seafood consumption. [6]


The ingestion of water contaminated with microplastics is the main exposure route for marine and freshwater species. [6] [7] In addition to contaminated water, farmed animals are often fed with fish meal products which may also be contaminated with microplastics. [6] We can thus see how easy it is for microplastics to travel up the food chain to humans.

 

Microplastics are easily inhaled from the environment. [8] There are traces of microplastics in both indoor and outdoor air.  However, the concentration indoors is far higher. [8] This could be as a result of fragmentation through heat and friction of plastic objects as well as plastic fibers released from synthetic clothing and textiles. [8]

How They Affect You

BPA’s and phthalates are considered a hormone/endocrine disruptor. [5] [9] These toxic chemicals mimic the hormone molecules within the body, more commonly reproductive hormones. [9] Our nuclear receptors recognize the molecule (e.g. BPA) and the molecule is subsequently able to interact with our bodily receptors at a low dosage. [9]

 

Biologically active levels of BPA detected in human blood, are noted to be within or above the range demonstrated in in vitro studies. The in vitro studies carried out at these concentrations have resulted in changes in the function of human tissue, and this is greatly concerning. [11]

 

BPA was shown to affect early embryonic development as well as exert late effects on postnatal development in mice. [2] Furthermore, when developing rodents are exposed to endocrine disrupting molecules, an advancement was seen in puberty as well as an alteration in reproductive function. [2] [10] The same phenomenon can be seen in humans too - for example, earlier sexual maturation and menstruation in girls compared to 20+ years ago.

 

According to the World Health Organization, cancer is the second leading cause of death worldwide, with breast cancer being in the top 5 causes of cancer death.

 

Breast tissue is sensitive to estrogen and this includes xenoestrogens too. [12] Some breast cancer cells are hormone sensitive, which essentially means that if the cancer cells are exposed to the hormone, they will grow. This effect is the exact opposite of what we are trying to achieve where cancer cells are concerned. Individuals with a family history of estrogen-sensitive breast cancer should be particularly aware of their exposure to xenoestrogens. Plastics have shown the potential to increase the aggressiveness of cancer due to their estrogenic effects in the body. [12] In addition, studies suggest that uterine myometrium may have similar profiles of sensitivity to estrogen. The study reveals that rats develop uterine leiomyomas following exposure to xenoestrogens. When rats are given Tamoxifen, the incidence of leiomyoma decreases. [12]

 

Men, don’t stop reading.  You are not safe from the dangers of plastic toxins either! Increased phthalates concentrations in the body were inversely correlated to sperm morphology. [2] Sperm morphology refers to the size and shape of sperm. Abnormal sperm morphology may affect the ability of the sperm to reach and penetrate the egg, thus resulting in decreased fertility.

 

BPA has been associated with a number of additional health problems, such as ovarian chromosomal damage, decreased sperm production, rapid changes in immune system and even type-2 diabetes and cardiovascular disease. [2] [10] Plastic toxins are affecting us throughout the human life cycle - from a vulnerable developing fetus, to pubescent adolescents, through to your adult reproductive years. [2] [10] [13] The increasing amount of negative evidence of plastic toxins on the functioning of the human body, is enough to make you want to steer the bandwagon of the anti-plastic movement.

How To Protect Yourself

While it’s impossible to avoid plastic completely, there are a few steps that we can put in place in order to reduce our exposure.

  • Avoid covering food with plastic wrap.

  • Use stainless steel or glass water bottles.

  • Reduce the amount of canned foods that you eat.

  • Purchase your own reusable coffee mug if you purchase take-away coffee.

  • Use baby bottles that are labeled BPA free.

  • Avoid storing food in plastic. Use glass or ceramic.

  • Go straw-less by not asking for a straw at a restaurant or buy your own reusable straws.

  • Avoid heating food in plastic or roasting/steaming bags.

  • Avoid handling cash receipts where possible.

  • Avoid plastic labeled with the recycle symbol #3 as this plastic item will contain PVC.

  • Strive to eat more vegetarian meals to reduce consumption of plastic in the food chain.

  • Be aware of the textiles at home. Avoid nylon, acrylic and polyester.

Work with a naturopathic doctor / naturopath to help you assess for environmental pollutants and to understand how they may be affecting your health. The information on this website is a guide for ways to protect you and your family from environmental pollutants.  It is not meant to replace advice from a healthcare professional.

3 Essentials

  1. Avoid covering food with plastic wrap

  2. Use stainless steel or glass water bottles

  3. Reduce the amount of canned foods that you eat

Additional Key Recommendations

  1. Purchase your own reusable coffee mug if you purchase take-away coffee

  2. Use baby bottles that are labeled BPA free

  3. Avoid storing food in plastic. Use glass or ceramic.

  4. Go straw-less by not asking for a straw at a restaurant or buy your own reusable straws

  5. Avoid heating food in plastic or roasting/steaming bags.

  6. Avoid handling cash receipts where possible.

  7. Avoid plastic labeled with the recycle symbol #3 as this plastic item will contain PVC.

  8. Strive to eat more vegetarian meals to reduce consumption of plastic in the food chain.

  9. Be aware of the textiles at home. Avoid nylon, acrylic and polyester.

References

  1. Rahman M, Brazel CS. The plasticizer market: an assessment of traditional plasticizers and research trends to meet new challenges. Progress in Polymer Science. 2004; 29 (12):1223–1248.

  2. Ikezuki Y, Tsutsumi O, Takai Y, Kamei Y, Taketani Y. Determination of bisphenol A concentrations in human biological fluids reveals significant early prenatal exposure. Hum Reprod. 2002 Nov;17(11):2839-41. 

  3. Lakind J, Naiman D. Bisphenol A (BPA) daily intakes in the United States: Estimates from the 2003-2004 NHANES urinary BPA data. J Expo Sci Environ Epidemiol. 2008 Nov;18(6):608-15.

  4. Hervey G. Plastics that save us may also hurt us. Politico.eu.  https://www.politico.eu/article/plastics-blood-bags-dehp-may-damage-humans/. Published May 9, 2019.

  5. Meeker J, Sathyanarayana S, Swan S. Phthalates and other additives in plastics: human exposure and associated health outcomes. Philos Trans R Soc Lond B Biol Sci. 2009 Jul 27; 364(1526): 2097–2113.

  6. Nara R. Microplastic contamination of the food supply chain. Foodsafetymagazine.com. https://www.foodsafetymagazine.com/magazine-archive1/december-2018january-2019/microplastic-contamination-of-the-food-supply-chain/. Published Dec 2018.

  7. The Straight’s Times Staff. Plastics have entered food chain, study shows. Straitstimes.com. https://www.straitstimes.com/world/europe/plastics-have-entered-human-food-chain-study-shows. Published Oct 23, 2018.

  8. Luo K. Are you breathing plastic air at home? Here’s how microplastics are polluting our lungs. World Economic Forum Website. https://www.weforum.org/agenda/2018/06/microplastic-pollution-in-air-pollutes-our-lungs/. Published June 4, 2018.

  9. Li L, Wang Q, Zhang Y, et al. The Molecular Mechanism of Bisphenol A (BPA) as an Endocrine Disruptor by Interacting with Nuclear Receptors: Insights from Molecular Dynamics (MD) Simulations. PLoS One. 2015; 10(3); e0120330.

  10. Howdeshell, K., Hotchkiss, A., Thayer, K. et al. Exposure to bisphenol A advances puberty. Nature. 1999; 401:763–764. https://doi.org/10.1038/44517.

  11. Proshad R, Kormoker T, Isalm M, Haque M. Toxic effect of plastic on human health and environment: A consequence of health risk assessment in Bangladesh. International Journal of Health. January 2018; 6:1-5.

  12. Eskenazi B, Warner M, Samuels S, et al. Serum Dioxin Concentrations and Risk of Uterine Leiomyoma in the Seveso Women's Health Study. American Journal of Epidemiology. July 2007; 166(1):79–87.

  13. Meeker J; Sathyanarayana S; Swan S. Phthalates and other additives in plastics: human exposure and associated health outcomes. Philos Trans R Soc Lond B Biol Sci. 2009 Jul 27; 364(1526): 2097–2113.